1. Field of the Invention
This invention relates generally to the field of surgical procedures, and in particular to the placement of a suture in tissue. More specifically, the invention relates to suture placement devices and techniques for less invasive surgical procedures within the heart and great vessels.
Various types of surgical procedures are currently performed to investigate, diagnose, and treat diseases of the heart and the great vessels of the thorax. Such procedures include repair and replacement of mitral, aortic, and other heart valves, repair of atrial and ventricular septal defects, pulmonary thrombectomy, treatment of aneurysms, electrophysiological mapping and ablation of the myocardium, and other procedures in which interventional devices are introduced into the interior of the heart or a great vessel.
Of particular interest to the present invention are intracardiac procedures for surgical treatment of heart valves, especially the mitral and aortic valves. According to recent estimates, more than 79,000 patients are diagnosed with aortic and mitral valve disease in U.S. hospitals each year. More than 65,000 mitral valve and aortic valve replacement procedures are performed annually in the U.S., along with a significant number of heart valve repair procedures.
Various surgical techniques may be used to repair a diseased or damaged vessel, including annuloplasty (contracting the valve annulus), quadrangular resection (narrowing the valve leaflets), commissurotomy (cutting the valve commissures to separate the valve leaflets), shortening mitral and tricuspid valve chordae tendonae, reattachment of severed mitral or tricuspid valve chordae tendonae or papillary muscle tissue, and decalcification of valve and annulus tissue. Alternatively, the valve may be replaced, by excising the valve leaflets of the native valve, and securing a replacement valve in the valve position, usually by suturing the replacement valve to the natural valve annulus. Various types of replacement valves are in current use, including mechanical and biological prostheses, homografts, and allografts, as described in Bodnar and Frater, Replacement Cardiac Valves, 1-357 (1991). A comprehensive discussion of heart valve diseases and the surgical treatment thereof is found in Kirklin and Sir Brian Barratt-Boves, Cardiac Surgery, 323-459 (1986).
When investigating, diagnosing, or treating diseases of the heart and the great vessels of the thorax, many current techniques require a gross thoracotomy, usually in the form of a median sternotomy, to gain access into the patient's thoracic cavity. A saw or other cutting instrument is used to cut the sternum longitudinally, allowing two opposing halves of the anterior or ventral portion of the rib cage to be spread apart. A large opening into the thoracic cavity is thus created, through which the surgical team may directly visualize and operate upon the heart and other thoracic contents.
Less-invasive surgical procedures have recently been developed which avoid the need for a gross thoracotomy, such as a median sternotomy. In such less invasive procedures, access to the thoracic cavity is obtained through percutaneous penetrations within intercostal spaces of the rib cage. Through such intercostal penetrations, surgical instruments may be inserted to therapeutically treat the heart or thoracic contents. For example, U.S. Pat. No. 5,571,215, the disclosure of, which is hereby incorporated by reference, describes techniques for less-invasive heart valve replacement wherein a diseased heart valve may be replaced with a prosthetic valve utilizing small-profile instruments introduced through percutaneous access ports, incisions or punctures between the ribs. Similarly, application Ser. No. 08/485,600, filed Jun. 7, 1995, which is incorporated herein by reference, discloses techniques for repair of cardiac valves by securing an annuloplasty ring to the valve annulus using instruments positioned through small, percutaneous access ports between the ribs.
Common to many cardiac surgical procedures is the need to place sutures in heart or other tissue within the thoracic cavity. For example, in the case of heart valve repair or replacement, the valve prosthesis or annuloplasty ring is usually sutured to tissue on or around the patient's native valve annulus.
Placing sutures in heart or other tissue that is accessed from outside of the patient's chest through small access ports presents a variety of difficulties. For instance, maneuverability is often difficult due to the limited space between the ribs. Further, when accessing the contents of the thoracic cavity through an intercostal space, visibility is limited, thereby making it difficult to properly place the suture. Further, such procedures can become timeconsuming, particularly when placing a single suture at a time. Placing sutures in an annulus of a heart valve for attachment of a replacement valve or annuloplasty ring is especially challenging. The suture needle must be inserted through the valve annulus in a direction toward or away from the surgeon, creating difficulty in seeing and manipulating the needle as it is passes through the annulus. Frequently, a curved needle is used in order to drive the needle deeper into the annulus tissue so that the suture will not tear out of the tissue. However, such a curved needle must be driven in an arc about an axis parallel to the plane of the annulus, whereas in less-invasive procedures, the surgical approaches used to access the heart valves dictate that the needleholding instrument be oriented at an angle perpendicular to the plane of the annulus. The needle must therefore be driven in a curved path about an axis roughly perpendicular to the shaft of the instrument. With the angular motion of the instrument highly limited when positioned through a small intercostal access port, the ability to drive a curved needle in an arcuate path through the valve annulus is greatly compromised.
What is needed, therefore, are devices and methods for improved suture placement when access to the tissue is limited, such as in less-invasive surgical procedures. In particular, the devices and methods should allow for improved visibility of the needle as it is either placed into or removed from tissue. Preferably, the devices and methods will provide the ability to conveniently introduce the needle tip into tissue, remove it, and then replace it in a separate location in the event that the needle was initially misplaced. The devices and methods should also facilitate easy introduction and passage of the needle through tissue. The devices and methods should also reduce the time required to place the sutures. In a preferable aspect, the devices and methods should facilitate the placement of sutures in a native valve annulus in the heart for attachment of various types of protheses, including mechanical and biological prostheses, homografts, allografts, annuloplasty rings, and the like. The devices and methods should further facilitate driving a curved suture needle in an arcuate path through the native valve annulus using an instrument oriented perpendicular to the plane of the annulus. The devices and methods should be useful not only in conventional open surgical procedures, but should be suitable for use through small percutaneous access ports in less-invasive surgical procedures as well.
2. Brief Description of the Background Art
A variety of suturing instruments are described in U.S. Pat. Nos. 4,027,608; 4,235,177; 4,406,237; 4,414,908; 4,417,532; 4,440,171; 4,465,070; 4,474,358; 4,484,580; 4,553,544; 4,557,265; 4,899,746; 5,152,769; 5,224,948; 5,308,353; 5,374,275; 5,403,328; 5,403,329; 5,403,329; 5,403,328; 5,224,948; and PCT Applications WO 94/05213, WO 94/15537 and WO 95/06447.
Product brochure, The Laurus In-line Endoscopic Suturing Device, Laurus Medical Corporation, Irvine, Calif., rev. 10/94, describes an "in-line needle driver" which includes an elongate shaft with an interior channel at a distal end of the shaft. The interior channel allows a needle to be loaded into the shaft so that needle is generally completely housed within the shaft when fully loaded.
Product brochure, Innovation Through Progress, Rema-Medizintechnik GmbH, describes a suturing device for closing wounds during laparoscopic operations. The device includes an elongate shaft having a pair of lateral needles which are generally parallel to the shaft. The needles may be extended away from the shaft after insertion of the device through endoscopic working channels so that the needles may be pulled through the tissue.
U.S. Pat. No. 4,932,965 describes an artificial valve having a holder for holding sutures and needles used when implanting the valve.